Bits that are used in mining and for removing road surfaces are typically mounted in a machine having a power driven cutting wheel.
When employed on abusive material such as concrete, the attack bits encounter high pressures and undergo excessive steel wear around the tip section. Currently employed conically shaped tips not only experience degrees of blunting, thereby reducing machines speed, but also suffer from the presence of manufacturing flaws which can lead to total bit failure.
One example of commercially successful bits is described in U.S. Pat. No. 4,497,520, issued on Feb. 5, 1985 to Ojanen and assigned to the same assignee as the present invention. The patent discloses and claims a rotatable cutting bit where the head portion consists of a base section, a conical tip section with a maximum diameter, and an intermediate section contiguous with the base and tip sections. Under manufacturing conditions the dies used in forming these bits experience wear at the point of maximum tip diameter (the seam) resulting in unwanted accumulation of uncompressed carbide material (flashing). Commonly known methods of polishing, such as mechanical tumbling, remove the flashing but generate stress cracks along the same thereby increasing the likelihood of bit failure.
As a consequence of the commercial success of assignees Patent No. 4,497,520, consideration has now been given to improvements in construction relative to methods of manufacture for such tooling for better quality and control in production volumes.